Renowned for his paintings inspired by cartoons and advertising imagery, painstakingly hand-coloured with dots, Roy Lichtenstein was an art-world game-changer as much for his work's intellectual rigour as for its visual power, says George Pendle.

In 1970, Laurence Graff created the 'Hair & Jewel', an arrangement of Graff jewels showcased within a magnificent hairstyle. The image was seen around the world and broke with convention, displaying diamonds in a way never seen before. Now, in celebration of Graff's enduring success, this incredible coiffure has been re-created, writes Jo Glasbey.